The present invention relates to a series of heterocyclic compounds having hypoglycemic and anti-diabetic activities, and provides processes for their preparation and methods and compositions for their use.
It is known that compounds which, like those of the present invention, contain, inter alia, a thiazolidinedione or oxazolidinedione group attached, via a methylene or methylidene group, to a benzene ring have this type of activity. Compounds of this general type are disclosed in European Patent Publications No. 008 203, 139 421, 441 605, 208 420, 528 734, 177 353, 306 228 and 356 214, and in WO 92/07850, 92/07839, 91/07107, 92/02520 and 92/03425. We have now discovered that the inclusion in such compounds of certain specific bicyclic nitrogen-containing ring systems results in compounds of much improved activity.